ABSTRACT

Deba area is intensely affected by frequent shallow landslides triggered by rainfall. This contribution explores the role of rainfall in landslide activity during a quite long time span (60 years), from a large network of rainfall gauges and a complete inventory of landslides. Out of 1,180 landslides inventoried, more than 50% occurred simultaneously in 6 known dates, corresponding to 6 episodes triggering multiple landslides; 3,241 rainfall episodes have been automatically recognized and characterized in terms of rainfall amount and duration, providing a representative dataset that covers a wide range of movement types and behaviors.The relationship between rainfall episodes driving multiple movements simultaneously has not been explored in depth so far in northern Spain. The extraordinary character of the triggering rainfall has been assessed and empirical rainfall thresholds (total amount, and mean intensity), producing multiple landslides, have been found and compared with others described in the literature. Also, the meteorological conditions associated to those extreme events have been recognized: multiple landslide occurrences are triggered by extreme convective rainfall: intense, short and with limited horizontal extent, as well as a marked summer-autumn seasonality. This weather pattern is more characteristic of Mediterranean areas than of mild marine west-coast climates.

摘要

德巴地区受到降雨引发的频繁的浅层滑坡的严重影响。这项贡献从大型雨量计网络和完整的滑坡清单中探讨了降雨在相当长的时间跨度（60 年）中在滑坡活动中的作用。在 1,180 处已盘点的滑坡中，超过 50% 在 6 个已知日期同时发生，对应于 6 次触发多处滑坡；3,241 个降雨事件已被自动识别并根据降雨量和持续时间进行表征，提供了一个涵盖广泛运动类型和行为的代表性数据集。西班牙北部。已经评估了触发降雨的异常特征，并发现了产生多个滑坡的经验降雨阈值（总量和平均强度），并与文献中描述的其他降雨阈值进行了比较。此外，与这些极端事件相关的气象条件已得到确认：多起滑坡事件是由极端对流降雨引发的：强烈、短暂且水平范围有限，以及明显的夏秋季节。这种天气模式更具有地中海地区的特征，而不是温和的西海岸海洋气候。与这些极端事件相关的气象条件已得到确认：多起山体滑坡事件是由极端对流降雨引发的：强烈、短暂且水平范围有限，以及明显的夏秋季节。这种天气模式更具有地中海地区的特征，而不是温和的西海岸海洋气候。与这些极端事件相关的气象条件已得到确认：多起山体滑坡事件是由极端对流降雨引发的：强烈、短暂且水平范围有限，以及明显的夏秋季节。这种天气模式更具有地中海地区的特征，而不是温和的西海岸海洋气候。